Signaling system



A. s. BENJAMIN SIGNALING SYSTEM May 2, 1933;

Filed June 5, 19:50

. INVENTOR:

ABRAHAM s. BENJAMIN; 4 BY ATTORNEY Patented May 2, 1933 UNITED STATES PATENT ol-rlca ABRAHAM S. BENJAMIN, OF CHICAGO, ILLINOIS, ASSIGNOB TO TELETYPE CORPORA- TION, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE SIGNALING SYSTEM Applicationfiled June 3, 1930. Serial No. 459,058.

My present invention relates to signaling systems and more particularly to telegraph systems of the automatic printing telegraph type in which a motor is required for operating the printing mechanism.

In some printing telegraph systems, the volume of trafiic is so small that it is practical to keep the printer motors normally at rest and to start them into operation when a message is to be received or sent, rather than to keep them running continuously. The motors preferably are kept running only until the conclusion of the message in such systems.

In such printing telegraph systems it is necessary that the operator at any station shall be able at will to initiate communication with the operator at a remote station. Difficulties however have been experienced with such systems in that the calling operator may start signaling before the called operators apparatus is in condition for operation. I have found therefore that it is highly desirable for an operator to be able not only to start the printer motor at the remote station, but to receive indications that the motor is in operation and that the remote station is ready to receive messages.

Accordingly, an object of my invention is to provide improved methods and means in normally non-operating signaling systems for initiating communication from either end thereof.

A still further object of my invention is to provide methods and means in normally non-operating signaling systems in which the apparatus at the calling party station is initiated into operation after the apparatus at the ca led station has been started into operation.

Many stations connected in signaling systerms are not provided with direct current from a local power company and the trafiic does not warrant the installation of an expensive storage battery set. There is, however, usually available alternating current from a local power company. Accordingly a further object of my invention is to provide improved methods and means in normally non-operating signaling systems in which the terminal stations are provided only with alternating current supply, for starting up communication from either end of the line.

A still further object of my invention is to provide improved methods and means in normally non-operating signaling systems whereby the necessity for storage batteries for controlling and carrying on communicatlon from either end of the system, is eliminated.

Another object is to provide an improved telegraph system in which the printer motors and motor generator sets at two terminal stations may be started or stopped by the operator at either station.

The various features and the foregoing objects as well as other objects of the invention will be more fully understood upon reference to the following detailed description taken in connection with the accompanying drawing, while the scope of the invention will be particularly pointed out in the appended claims.

In the drawing, the figure is a circuit diagram showing the equipment at two terminal stations and two main stations and the circuit connections therebetween.

Referring to the drawing, the two main stations 10 and 10 are interconnected by a duplex circuit including a single line conductor 11. Two line conductors 12 and 13 connect main station 10 to a terminal station 14. Similarly, two line conductors 12 and 13 connect main station 10 to a terminal station 14.

The main station 10 comprises the apparatus embraced within the dot-dash parallelogram; namely, a line relay 15, a network 16 for balancing the signaling line 11, a sending relay 17 and resistances 18, 19, 20 and 21 interposed between sources of positive and negative direct current potential indicated by plus and minus signs and the signaling lines to prevent short circuits.

The line relay 15 is of the polar type and has its armature 22 connected to the line conductor 12. The relay 15 is provided with two windings one of which is connected to line conductor 11 and the other is connected to the to each other and to the armature 23 of the relay 17 in a manner well known in the art. The relay 17 is of the neutral type and has one of its terminals connected through resistance 20 to positive battery and the otherterminal to line conductor 13. The armature 23 of rela 17 is normally urged into engagement with its back contact by a spring 24.

The line conductors 12 and 13 are connected to jacks 25 and 26, respectively, at the terminal station 14. An additional jack 27 is provided for a purpose which will appear hereinafter. The apparatus at the terminal station 14 is connected to plugs 28, 29 and 30. By providing jacks and plugs at the terminal station, a printer or transmitter which, for any reason breaks down while operating may quickly be replaced by another printer or transmitter which is in proper adjustment.

As previously pointed out, the only form of power available at the terminal stations is alternating current which is unsuitable for operation of the line circuit of the telegraph system. Accordingly a'motor generator set 3233, is provided at the terminal station 14 for converting the alternating currents available from the supply mains 34 into direct current. The alternating current supply is controlled by a main power switch 35 and an alternating current relay 36 is provided for controlling the starting and stopping of the motor 32. The alternating current relay 36 also controls a motor 37 for operating a re-v ceiving printer represented diagrammatically by printer magnet 38. Relay 36 also controls a motor 39 for operating a home record printer represented diagrammatically by the printer magnet 40. The motors 32, 37 and 39 are connected in parallel so that operation of alternating current relay 36 controls all of them simultaneously.

Printing magnet 38 is connected in a circuit comprising plug 28 and polar relays 41 and 42 all connected in series. The armatures 43 and 44 of these polar relays are normally biased by individual springs 45 and 46, re-' spectively, for opening their contact points when current is not flowing through the windings of these relays. The polar relay 41 at its armature 43 controls the energization of the winding of alternating current relay 36. The armature 44 of polar relay 42 controls the energization of a slow-to-deenergize relay 47 which is provided with two armatures 48 and 49.

The relay 47 at its armature 48 controls a shunt circuit around the contacts 51 and 52 of a manually operable switch 53. Switch 53, which controls the starting and stopping of the motors as will be described hereinafter, comprises a switch arm 54 which is operable by means of a handle 55 to occupy any one of three positions; namely, engagement with the generator 33. The circuit for the relay 47 extends from the positive terminal of generator 33 over a resistance 61, armature 44 in engagement with its lower contact, Winding of relay 47 and then to the negative terminal of the generator 33. Energization of relay 47 closes at its armature 49 the circuit forthe relay 57, this circuit extending from positive terminal of generator 33 over resistance 62, armature 49 in engagement with its front contact, winding of relay 57 and then to the negative terminal of the generator.

The magnet 40 of the home record printer is connected in series with a transmitter 63 and the plug 29. The transmitter may be of any well known type. The equipment and electrical connections at main station 10' are similar to the equipment and connections at main station 10. Also the equipment and electrical connections at terminal station 14' are similar. to the equipment and connections at terminal station 14. r

The normal condition of the. system will first be described. The plugs 28, 29 and 30 are inserted in their corresponding jacks 25, 26 and 27, respectively. The switch 53 is in the position shown in the drawing with switch arm 54 in engagement with contact 51. With the switch in this position, the circuit of sending relay 17 at the main station 10 is open. Its armature 23 is therefore maintained in engagement with its back contact due to the bias of spring 24 and negative batteryis extended over resistance 18 and armature 23. The current thereafter flows through the lower winding of polar relay 15. Negative current flowing through winding of relay 15 operates armature 22 to its lower contact as shown. As will appear hereinafter, negative current from the sending relay 17' also flows through the windings of relay 15'. Armature 22' of polar relay 15' is therefore held in the open position as shown. Accordingly, line 12'is open and printer magnet 38 of the rece ving printer and polar relays 41 and 42 at terminal station 14 are all deenergized. The armature 43 of polar relay 41 is therefore held in its biased or open position sothat alternating current relay 36 is deenergized and motors 32, 37 and 39 are at rest. The slow-to-deenergize relays 47 and 57 are at this time deenergized by reason of the fact that generator 33 is not operating and also because of the open circuit at armature 44.

energized condit on of relay 17 causes negative current to flow to relay 15' as stated above. The negative current flowing through relay 15' maintains armature 22' in the position shown and as a result relays 41' and 42' and magnet 38 are deenergized. Accordingly the remaining apparatus is in corre* sponding condition. No current flows on wire 11 since the negative potential at one end balances the negative potential at the other end.

Operation It will now be assumed that the operator at terminal station 14 desires to communicate with the operator at terminal station 14'. To this end he first will shift the manual starting switch 53 to the position in which switch arm 54 engages contact 52.

This establishes a circuit extending from positive battery at main station 10 through resistance 20, winding of sending relay 17, linewire 13, jack 26, plug 29, home printer magnet 40, transmitter 63, plug 29, jack 26, jack 27, plug 30, switch arm 54, contact 52, plug 30, jack 27 to ground.

Sending relay 17 energizes and establishes a circuit extending from positive battery through resistance 19, front contact and armature 23 of relay 17', upper winding of line relay 15, over line 11, line relay 15' and through network 16' to ground.

Relay 15' energizes and establishes a circuit extending from positive battery through resistance 21', front contact and armature 22', line wire 12', jack 25, plug 28', receiving printer magnet 38, polar relay 41', polar relay 42, plug 28', jack 25' to ground. As a result of this circuit, polar relays 41' and 42' energize.

Energization of polar relay 41 establishes a circuit for alternating current relay 36, this circuitextending from one of the alternating current mains 34' through the winding of alternating current relay 36, armature 43' and thence to the other alternating main 34'. Alternating current relay 36. energizes and extends the power circuit 34 to the motor 32' and printin motors 37 and 39'. The motor 32' drives t e generator33 and direct current becomes available for the operation of slow relays 47 and 57 Energization of polar relay 42 establishes an erator 33.

energizing circuit for slow relay 47', this circuit extending from the positive terminal of generator 33 over resistance 61', armature '44, through the Winding of slow relay 47 and thence to the negative terminal of gen- Slow relay 47 energizes and at armature 48' establishes a shunt circuit around the contacts 51' and 52 of the switch 53. At armature 48' the relay 47 establishes a line circuit for energizing sending relay 17' at main' station 10' this circuit extending from positive battery at the main station 10 through resistance 20, winding of the sending relay 17, line wire 13, jack 26, tip of plug 29, printing magnet 40, transmitter 63', sleeve of plug 29', jack 26', jack 27, tip of plug 30',

switch arm 54, contact 51', armature 48 in engagement with its front contact, sleeve of plug 30' and jack 27 to ground.

Energization of sending relay 17 establishes a circuit for reversing the cnergization of the line relay 15 at station 10 this circuit extending from positive battery through resistance 19, front contact and armature 23', lower winding of line relay 15, and network 16' to ground. No current flows on wire 11, since the positive potential at one end balances the positive potential at the other end. The current through 19, 23, 15, 16 at station 10 operates relay 15. Energization of line relay l5 establishes a circuit for energizing polar relays 41 and 42 at terminal station 14. This circuit extends from positive battery at main station 10 through resistance 21, armature 22, line 12, jack 25, tip of plug 28, magnet 38 of the receiving printer, polar relays 41 and 42, sleeve of plug 28 and jack 25 to ground.

Energization of polar relay 41 operates its armature 43 from its biased position to the lower contact which establishes an energizing circuit for the alternating current relay 36, this circuit extending from one power main 34 through armature 43, winding of relay 36 and thence to the other main 34. Energization of alternating current relay 36 extends the power circuit 34 to the motor 32, and printer motors 37 and 39. The motor 32 drives the generator 33 and direct current becomes available at terminal station 14. Energization of polar relay 42 establishes a circuit for slow to release relay 47. This circuit extends from the positive terminal of generator 33 through resistance 61, armature 44, through the winding of slow to release relay 47 and thence to negative terminal of generator 33.

Slow to release relay 47 energizes and at armature 48 establishes a shunt circuit around the contacts 51 and 52 of the switch 53. At armature 49, the relay 47 establishes an energizing circuit for slow to release relay 57 extending from positive terminal of generator 33, through resistance 62, armature 49, winding of slow to release relay 57 and thence to negative terminal of generator 33. Slow to release relay 57 energizes and establishes a shunt circuit around the contacts of polar relay 41. This shunt circuit maintains the circuit through the alternating current relay 36 closed independently of polar relay 41 so that operation of polar relay 41 in response to received code impulse conthe distant terminal station 14 have been started and that the apparatus at the distant station now is in condition to receive the code messages. As soon as the motors start, the operator shifts the switch 53 quickly to move the switch arm 54 into engagement with the contact 51. This is the normal position of the switch 55, both for operation and for resting. The circuit described in the above which extended through switch arm 54 and contact 52 now extends through switch arm 54, contact 51 and armature 48 of slow to release relay 47 in engagement with its contact.

The apparatus is now in condition for the transmission of code messages fromeither terminal station to the other. The operator at terminal station 14 operates the transmitter 63, and the transmitted message is recorded upon the home printer 40 and also upon the receiving printer 38' at the distant terminal station 14. Closure of one or more of the contacts at transmitter 63 establishes a circuit extending from positive battery at main station 10 through resistance 20, winding ofsending relay 17, line 13, jack 26, tip of plug 29, printer magnet 40, closed contact of transmitter 63, sleeve of plug 29, jack 26, jack 27, plug 30, switch arm 54, contact 51, armature 48 in engagement with its contact, plug 30 and jack 27 to ground. Sending relay 17 energizes and establishes a circuit extending from positive battery, through resistance 19, front contact and armature 23, winding of polar relay 15, line 11, polar relay 15 and network 16' to ground. Polar relay 15 operates its armature into engagement with its upper contact establishing a circuit from positive battery at main sta tion 10 through resistance 21, armature 22', line 12, jack 25, tip of plug 28', receiving printer magnet 38, polar relays 41' and 42', sleeve of plug 28 and jack 25 to ground. Operation of polar relay 41 this time has no effect on alternating current relay 36 because the contacts of relay 41' are now shunted by the circuit extending through armature 58 of slow to release relay 57. Also operation of polar relay 42 has no effect at this time because of the retarded action of slow relay 47'.

respective contacts. Two slow-to-deenergizerelays are employed in .order to extend the time period during which the circuit connec- 'tions will be maintained to somewhat more ban the period necessary for the transmission of a complete code combination. Thus in the event that relay 47 should become'deenergized, a considerable time interval will elapse before the slow-to-deenergize relay 57 will release its armature to open the shunt circuit around the contacts of polar relay 41.

Should the operator at the distant terminal station 14 desire to reply immediately, he operates the transmitter 63 and the message transmitted is recorded upon the print-' is so designed as to hold its arma er 40' at terminal station 14' and upon the.

receiving printer 38 at station 14. During the transmission of such message, the relay 41 will vibrate its armature in accordance with the received impulse conditions, but this will not affect the alternating current relay 36, because the circuit thereof is held' closed by the slow-to-deenergize relay 57.v

The switch 53 at station 14-, where the transmission was initiated, having been re stored to its normal position with the switch arm 54 in engagement with the contact 51 and the switch 53' at the dista'ntterminal station 14 being also in normal position,

the operator at either terminal may now stop f the motor of the two stations.

Assuming the operator at home station 14 desires to stop the operation-of the system.

To do this he shifts the manual switch 53 into its middle position, thus isolating the switch arm 54 from both of its contacts and thereby interrupting the first line circuit described above. This deenergizes the sending relay 17 at the main station 10 so that its armature 23 moves into engagement with its back contact, establishing a circuit which extends from negative battery through resistance 18, armature 23, relay 15, line. 11,

relay 15', network 16-to ground. Negativecurrent flowing through line relay 15' moves its armature into engagement with its'lower contact thereby opening the circuit'of the; polar relays 41' and 42 at terminal station Relay 42' deenergizes and opens theafter a predetermined time delay opens the shunt circuit around the contacts of relay 41'. The contacts of relay 41 being already open the alternating current rela 36' is deenergized and the motors at terminal station 14' are stopped.

Deenergization of slow relay 47 also opens at armature 48' the circuit of the sending relay 17' at main station 10'. Relay 17' deenergizes and establishes a circuit from neg ative battery through resistance 18', armature 23, relay 15, line 11, relay 15, network 16 to ground. Negative current flowing through the relay. 15 operates its armature into engagement with its lower contact thereby opening the circuit of polar relays 41 and 42 at home terminal station 14. Polar relays 41 and 42 deenergize and move their respective armatures into engagement with their upper contacts. Deenergization of relay 42 opens the circuit of slow relay 47,

which after a predetermined time delayopens the circuit of slow relay 57 and the latterafter a predetermined time delay opens the shunt circuit around the contacts of relay 41. The contacts of relay 41 being already open, the alternating current relay 36 is deenergized and the motors at terminal station 14 are stopped. The operator at the home terminal station 14 noting that the motors have stopped then restores the manual switch 53 to its normal position as shown in the drawing, thus placing the home station 14 in condition to be started by the distant terminal station 14.

If preferred, the calling station operator in order to call the distant station may remove plug 30 from jack 27, instead of operating switch 53. A direct ground connection to conductor 13 will then be provided through contact instead of extending through switch 53. Similar provision for station 14' is made at contact 65.

Although I have shown a preferred embodiment of my invention in a duplex system, it will be clear that it is within the scope of my invention to apply it to other forms of systems and my invention is not limited to the specific illustration I have chosen for describing my invention, but is defined by the terms of the appended claims. Accordingly having described a preferred embodiment only of my invention what is desired to be secured by Letters Patent and is claimed as new is:

1. In a signaling system, a first terminal station, a second terminal station, motormechanism at each of said terminal stations, means atsaid first terminal station for controlling the starting and the continuous operation of the motor-mechanism at said second terminal station, and means responsive to the starting and continuous operation of the motor-mechanism at said second terminal station for controlling the starting of the motor-mechanism at said first terminal station.

2. In a signaling system, a first terminal station, a second terminal station, motorgenerator sets at each of said terminalsta tions, means at said first terminal station for controlling'the starting of the motor-generator set at said second terminal station, and means responsive to the starting of the motor-generator set atisaid second terminal station for controlling the starting of the motor-generator set at said first terminal station.

3. In a telegraph system, a first termina station, a second terminal station, printer operating motors at each of said terminal stations, means at said first terminal station for controlling the starting of the printer operating motors at said second terminal station, and meansresponsive to the starting of the printer operating motors at said second'terminal station for controlling the starting of the printer operating motors at said first terminal station. 4

4. In a telegraph system, a first terminal connections between said stations, a motor generator set at each of said statlons, a motorcontrol'relay at each of sald stations for controlling said motor generator set, a manually electrical connections between said terminal stations, a manually operable switch at said first terminal station for controlling the starting operation of the motor generator set at said second terminal station, means responsive to starting of the motor generator set at said second terminal station for starting the operation of the motor generator set at said first station, a manually operable switch at said second terminal station for controlling the starting operation of the motor generator set at the first terminal station, and means responsive to starting of the motor generator set at the first terminal station for starting the operation of the motor generator set at the second terminal station.

6. In combination, a terminal station comprising normally non-operating transmitting and receiving apparatus, a main station comprising repeating apparatus, a source of direct current energy at said main station, and circuit connections between the transmitting and receiving apparatus at the terminal station, a second terminal station, electrical station and'the repeating apparatus at the main station for starting said terminal station apparatus into operation, said circuit being provided wth energy-solely from said direct current source.

7. In a telegraph system, a first terminal station, a second terminal station, a motor mechanism at each of said terminal stations, a first main station, a second main station, a first sending line and a first receiving line connecting said first terminal station to said first main station, a duplex line connectin said main stations, a second sending line an a second receiving line connecting said second main station to said second terminal station, means at said first terminal station for transmitting a start impulse over said first sending line to said first main station, means at said first main station for repeating the impulse over the duplex line to the second main station, means at the second main station for repeating the impulse over the second receiving line to the second terminal station, and means at the second terminal station responsive to the impulse for starting the motor mechanism at the second terminal station.

8. In a telegraph system, a first terminal. station, a second terminal station, a printer mechanism at each of said terminal stations, :1 first main station, a second main station, a first sending line and a first receiving line connecting said first terminal station to said first main station, a duplex line connecting said first main station to said second main station, a second sending line and a second receiving line connecting said second main station to said second terminal station, means at said first terminal station for transmitting a start impulse over said first sending line to said first main station, means at said first main station for repeating said impulse over said duplex line to the second main station,

means at said second main station for repeating said impulse over the second receiving line to said second terminal station, and means at said second terminal station responsive to said impulse for starting the printer mechanism at said second terminal station.

9. In a telegraph system, a first terminal station, a second terminal station, a printer mechanism at each of said terminal stations, a first main station, a second main station, a first sending line and a first receiving line connecting said first terminal station to said first main station, a duplex line connecting said first main station to said second main station, a second sending line and a second receiving line connecting said second main station to said second terminal station, means at said first terminal station for transmitting a start impulse over said first send-' tion for repeating said im ulse over the sec,- ond receiving line to sai second terminal station, means at said second terminal station responsive to said impulse for starting the printer mechanism at said second terminal station, means at said second terminal station responsive to the starting of the printer mechanism at said second terminal station for transmitting a start impulse over said second sending line to said second main station, means at said second main station for repeating said impulse over said duplex line to said first main station, means at said first main station for repeating said impulse over said first receiving line to said first terminal station, and means at said first terminal station responsive to said impulse for startingthe printer mechanism at said first terminal station.

10. In a telegraph system, a first station, a second station, normally non-operating printing apparatus at said first station, a source of direct current at said second station, means at said second station and provided with energy solel from said source for controlling the startmg of said printing apparatus at the first station in operation, and means including said source of direct current for signaling between said stations.

11. In a telegraph system, a first station, a second station, normally non-operating printing apparatus and a motor generator set at said first station, a source of direct current at said second station, means at said second station and provided with energy solely from said source for starting said printing apparatus and motor generator set in operation, means at said first station for thereafter maintaining said printing apparatus, and motor generator set in operation independently of said starting means and means including said source'for signaling between said stations.

12. In a telegraph system, a first station, a second station, normally non-operating printing apparatus and a motor generator set at said first station, a source of direct current at said second station, means at said second station and provided with energy solely from said source for starting said printing apparatus and motor generator set in operation, means at said first station for thereafter maintaining said printing apparatus and motor generator set in operation independently of said starting means, means including said source for signaling between said stations, and means controlled from said second station for rendering said motor generator set non-operative again.

13. In a telegraph system, a first station, a second station, normally non-operating printing apparatus and a motor generator set atsaid first station, a source of direct current at said second station, means at said Second station and provided with energy solely from said source for starting said printing apparatus and motor generator set in operation, means at said first station for' thereafter maintaining said printing apparatus and motorin operation independently of said starting means, means including said source for signaling between said stations, and means controlled from either station for rendering said motor generator set nonoperative again.

14. In a telegraph system, a first terminal station, a second terminal station, a repeater station, a source of direct current at said repeater station, printing apparatus at each terminal station normally in a non-operating condition, a motor generator set at each terminal station, and means including circuit connections and provided with energy solely from said source of direct current for starting the printing apparatus and the motor generator set at each terminal station from one of said stations.

15. In a telegraph system, a first terminal station comprising motor mechanism, a second terminal station comprising motor mechanism, a first main station, a second main station and means whereby the motor mechanism at said second terminal station may be started fromsaid first terminal station, said means comprising a manually operable switch at said first terminal station, a sending line connecting said first term inal station to said first main station, a duplex line connecting the first main station to said second main station, a receiving line connec'ing said second main station to said second terminal station, and a motor control relay at said second terminal station.

16. In a telegraph system, a first terminal station comprising motor mechanism, a second terminal station comprising motor mech anism, a first main station; a second main station; means whereby the motor mechanism at said second terminal station may be sarted from said first terminal station, said means comprising a manually operable switch at said first terminal station, a sending line 00" necting said first terminal station to said first main station, a signaling circuit connecting said first main station to said second main station, a receiving line connecting said second main station to said second terminal station and a motor control relay at said second terminal station, means whereby starting of the motor mechanism at said second terminal station starts the motor mechanism at said first terminal station, said last-mentioned means comprising a relay at said second terminal station responsive to the starting of the motor mechanism at said second terminal station, a sending line connecting said second terminal station to said second main station, a receiving line connecting said first main station to said first terminal stacurrent at each sfation, means for transmit- 1 ting an impulse from said first station to said second station, means at said second station responsive to said impulse for applying.

said. source of current thereat to start said motor mechanism at said second station,

means at said second station responsive to the starting of said motor mechanism for sending an impulse from said second station to said first station, and means at said first station responsive to said last mentioned im-" pulse for connecting the source of current thereat with the motor mechanism at first station.

18. In combination, a first station, a second station, each of said stations comprising printing mechanism, signaling lines connecting said stations, means at each s at-ion for transmitting code combinations of impulse conditions over said signaling lines, means at said first station for transmittinga starting impulse over said signaling lines to said second station, means at said second station responsive to said starting impulse for starting the printing mechanism at said sec ond station, means at said second station responsive to starting of the printing mechanism at said second station for transmitting a starting impulse over said signaling lines to said first station, and means at said first station responsive to said last mentioned impulse for starting the printing mechanism at said first mentioned station.

19. In combination, a first station, a second station, each of said stations comprising motor mechanism, signaling lines connecting said stations,-a transmitter at each station for transmitting code combinations of impulse conditions over said signaling lines, a receiver at each station for receiving said code combinations of impulse conditions, a manually operable switch at said first station for transmitting a starting impulse over said signaling lines to said second station, a relay at said second station responsive to said starting impulse for starting the motor mechanism at said second station, a second relay at said second station responsive to the starting of the motor mechanism at said second station for transmitting a starting impulse over said signaling lines to said first station, and a relay at said first station responsive to-said last mentioned impulse for starting the motor mechanism at said first mentioned station.

20. In combination, a first station, a second station, each of said stations comprising motor mechanism, signaling lines connecting said stations, said signaling lines includingimpulse over said signaling lines to said first station, and means at said first station responsive to said last mentioned impulse for starting the motor mechanism at said first station.

21. In combination, a first terminal station, a second terminal station, each of said stations comprising motor mechanism, signaling lines connecting said stations, said signaling lines including repeater mechanism, a transmitter at each station for transmitting code combinations of impulse conditions over said signaling lines, a receiver at each station for receiving said code combinations of impulse conditions, a manually operable switch at said first station for transmitting a starting impulse over said signaling lines to said second station, a relay at said second station responsive to said starting impulse for starting the motor mechanism at said second station, a second relay at said second station responsive to starting of the motor mechanism at said second station for transmitting a starting impulse over said signaling lines to said first station, and a relay at said first station responsive to said last mentioned impulse for starting the motor mechanism atsaid first station.

22.' In combination, a first station comprising a motor generator set and a source of alternating current, a second station comprising a motor generator set and a source of alternating current, signaling lines connecting said stations, a switch at said first station for transmitting an impulse over said signaling lines to said second station, a relay at said second station responsive to said impulse for connecting the motor of the motor generator set at said second station to the source of alternating current at said second station, a second relay at said second station responsive to the starting of said motor generator set for transmitting an impulse from said second station over said-signaling lines to said first station, and a. relay at said first station responsive to said last mentioned impulse for connecting the motor of the motor generator set at said first station to the source of alternating current at said first station.

23. In a telegraph system, a first station, a second station, normally non-operating moms:

printing apparatus at said first station, a normal y rent at said second station, a key at said first station controlling the operation of said source of direct current and means at said first station and provided with ener solely from said source of direct current or controlling the starting of said printing telegraph apparatus at the first station in operation.

24. In a signaling system, a calling station, a called station, signalin and receiving apparatus at each station, riving means therefor at each station, a source of power at each station for the driving means thereat, means at the called station responsive to a condition at the calling station for connecting the source of power with the driving means at the called station, and means at the called station operative subsequently to the actuation of the driving means thereat for establishing a condition at the calling station to indicate the connection of the source of power at the called station with the driving means thereat.

25. In a signaling system, a calling station, a called station, signaling and receiving apparatus at each station, unidirectional driving means therefor at each station, a source of power at each station for the driving means thereat, means at the called station responsive to a condition at the calling station for non-operating source of direct curconnecting the source of power with the driving means at the called station for causing the unidirectional rotation of the driving means, and means at the called station operative subsequently to the actuation of the driving means thereat for establishing a condition at the calling station to control the connection of the source of power at the calling station with the driving means thereat.

26. A method of signaling which includes the steps of establishing a condition at a calling station, transmitting that condition to a called station, utilizing the condition at the called station to control the generation of an electric current, and utilizing the elec tric current to control the establishment of a similar condition at the calling station.

27. In a signaling system, a calling station, a called station, a source of alternating current at each station, driving means at each station actuated by the alternating current, a direct current generator at each station driven by said means, means at the called station responsive to a signal condition from the calling station for connecting said source of alternating current to the driving means thereat to operate the direct current generator, and means r'esponsive to the operation of said generator for establishing a condition at the calling station to render the source of alternating current thereat eflective to drive said driving means.

28. In a telegraph system, a plurality of remote stations, printing telegraph mechanism at each of the stations, means at a calling one of the stations for establishing a 5 predetermined condition, means at the other station responsive upon the establishment of said condition for rendering the printing telegraph mechanism thereat efiective for the reception of a message comprised of permu- 1 tation code signals, and means responsive to the efiective condition of said printing telegraph mechanism at said other station for establishing a condition to render the printing telegraph mechanism at the said calling 15 station effective for communication.

29. In a printing telegraph system, a calling station, a called station, a signaling circuit interconnecting said stations, printing telegraph ap aratus at each station, driving 20 means there or at each station, a source of power at each station for the driving means thereat, means at the called station responsive to a condition at the calling station for connecting the source of power with the 25 driving means at the called .station, and means at the called station operating upon the actuation of the driving means thereat for establishing aLcondition at the calling station to indicate the connection of the source of power at the called station with the driving means thereat.

In testimony whereof I afiix my signature.

ABRAHAM S. BENJALHN. 

